1. Field of the Invention
The present invention relates to a terminal removal jig for removing a terminal by warping a securing lance within a connector housing.
2. Description of the Related Art
FIG. 8 is a conventional terminal removal jig 51 disclosed in JUM-A-62-188080.
The terminal removal jig has a size approximately equal to that of a pencil, and is composed of a bar-like grip 52, an unlocking pin 53 which protrudes from the tip of the grip 52, a terminal pushing pin 54 which protrudes movably from the tip of the grip 52 and located shorter than the unlocking pin 53 and a coil spring 55 for urging the terminal pushing pin 54 in a protruding direction.
FIGS. 9A to 9C sequentially show the process for removing a terminal 57 using the terminal removal jig 51.
As seen from FIG. 9A, a terminal 57 is accommodated in a terminal accommodating chamber 59 at the rear of a connector housing 58 of synthetic resin, and a tab 60 which serves as an electrical contact of the terminal 57 protrudes into a connector fitting chamber 61 at the front of the connector housing 58. In this state, releasing of the terminal 57 is prevented in such a manner that an elastic locking piece 62 which protrudes from an intermediate portion of the terminal 57 is brought into contact with a step 64 at the end of a space 63 successive from the connector fitting chamber 61 in an axial direction.
The connector housing 58 is a female type which has the connector fitting chamber 61, whereas the terminal 57 is a male type which has the tab 60. An electric wire 66 is crimped on the end of the terminal 57. The female-type connector housing 58 and the male-type terminal 57 constitute a female-type connector 56. A male connector (not shown) is fit in the connector fitting chamber 61. The tab 60 of the male terminal 57 is inserted in and connected to an electric contact of a female terminal within the male connector. In this specification, the connector 56 having the connector fitting chamber 61 is defined as a female connector, whereas a connector (not shown) having a front end corresponding to the connector fitting chamber 61 is defined as a male connector.
In FIG. 9A, the tip of the terminal removal jig 51 is inserted into the connector filling chamber 61 until the terminal pushing pin 54 is brought into contact with the tip of the tab 60. In this state, the terminal removal jig 51 is moved forward as seen from FIGS. 9B and 9C so that the unlocking pin 53 enters the space 63 where the elastic locking piece 64 of the terminal 57 is located. When the tip of the unlocking pin 53 is brought into contact with the elastic locking piece 64, it warps the elastic locking piece 62 so that the terminal 57 is eventually unlocked.
At the stage of FIG. 9B before unlocking, the terminal pushing pin 54 moves backwards while it compresses the coil spring 55 (FIG. 8). As seen from FIG. 9C, the elastic locking piece 62, while it is warped, gets over the step 64. Simultaneously, the terminal 57 is pushed by the terminal pushing pine 54 so that it moves backwards. Finally, the electric wire 66 is pulled to draw out the terminal 57 from the terminal accommodating chamber 59. The terminal 57 may be drawn out in the cases where the terminal 57 within the connector 56 exhibits poor conduction, the terminal 57 is impaired and an alien terminal is erroneously inserted, etc.
However, the conventional terminal removal jig 51 described above has the following defects. It is difficult to align smoothly the unlocking pin 53 with the elastic securing piece 57 for securing the terminal 57 so that some experience is required to do the work of unlocking the terminal 57. Owing to unfamiliarity with dealing with the terminal releasing jig, the unlocking pin 53 may be inserted into the other portion of the connector housing 58, the unlocking pin 53 may pick at the terminal 57 so that the terminal is deformed, or the connector housing 58 maybe damaged. Further, since the locking releasing pin 53 is slender and relatively sharp in its tip, a worker may be injured from the tip of the unlocking pin 53. The terminal removal jig 51, which is dedicated to the female connector 56, cannot be applied to a male connector (not shown). Therefore, the terminal removal jig which can be applied to the male connector and permits the terminal to be unlocked easily by anyone has been eagerly demanded.
An object of the present invention is to provide a terminal removal jig which can be applied to a male connector and easily aligned when a terminal is unlocked from a connector housing so that the terminal can be unlocked simply, easily and safely by anyone.
In order to attain the above object, in accordance with the invention, there is provided a terminal removal jig comprising: an outer case having a guide groove; a positioning member having a protruding portion at its tip which is to be engaged with a terminal insertion hole at a front end of a connector housing; an elastic body for urging the positioning member toward its protruding direction; and an unlocking plate secured on the outer case and having a unlocking pin at its tip, the unlocking pin being to be mated with an elastic locking lance within the connector housing.
In this configuration, by engaging the protruding portion at the tip of the positioning member in the terminal insertion hole of the connector, the position of the unlocking pin relative to the locking lance is defined accurately. Therefore, in this state, if the outer case is moved forward, the unlocking pin moves forward integrally to it to warp the locking lance so that the terminal is surely unlocked. In this case, while the positioning member moves backward, its protruding portion is always engaged in the terminal insertion hole, the position of the unlocking pin is always defined accurately. Thus, anybody can unlock the terminal simply and surely. Particularly, it is possible to unlock the terminal for the male connector having a terminal insertion hole simply and surely. Further, since an error of inserting the unlocking pin into the terminal insertion hole does not occur, an inconvenience of damaging or deforming the terminal within the connector by the tip of the unlocking pin can be prevented.
Preferably, in a free state of the positioning member, the tip of the unlocking pin is located behind the protruding portion of the positioning member. In this configuration, the tip of the unlocking pin is aligned with the positioning member and does not protrude externally. Therefore, an accident of injuring a worker by the sharp tip of the unlocking pin or damaging the connector housing can be prevented.
Preferably, the unlocking pin is kept in contact with the outer wall of the positioning member. In this configuration, the positioning accuracy of the unlocking pin relative to the positioning member or terminal insertion hole can be enhanced.
Preferably, in a state where the protruding portion is engaged in the terminal insertion hole, the tip of the unlocking pin faces a terminal removal jig insertion hole opposite to the locking lance. In this configuration, the unlocking pin has only to be moved forward so that it is inserted into the terminal removal jig insertion hole. This warps the locking lance to unlock the terminal surely.
Preferably, a protruding strip is formed on the outer wall of the positioning member, and a slit-like guide hole in which the protruding strip is slidably engaged is formed in the unlocking plate. In this configuration, the protruding strip is slidably engaged in the guide hole so that the unlocking plate, i.e. unlocking pin can be accurately positioned with respect to the positioning member.
Preferably, the inner wall of the slit-like guide hole is successive to the stem of the unlocking pin. In this configuration, since the protruding strip is located in contact with the stem of the unlocking pin, the alignment between the protruding strip, i.e. positioning member and the unlocking pin is accurately made, and the terminal can be removed more accurately.
Preferably, a protrusion serving as a stopper is formed on the positioning member, and a lengthy guide hole in which the protrusion is slidably engaged is formed in the unlocking plate. In this configuration, when the positioning member is urged by the elastic body so that it is protruded, the protrusion is brought into contact with the front end of the guide hole. Thus, the advancing limit of the positioning member can be accurately defined and the relative position of the tip of the unlocking pin to the protrusion can be accurately defined.